Abstract
BACKGROUND—Surface tension forces appear to make a significant contribution to upper airway closure in patients with obstructive sleep apnoea (OSA). It is possible that drying of the upper airway mucosa at night might contribute to these surface tension forces and the severity of OSA might therefore change with alteration of the ambient humidity. METHODS—A randomised single blind crossover study of high ambient relative humidity (HRH) versus low ambient relative humidity (LRH) was performed in 12 men of mean (SD) age 49 (9) years with mild OSA (apnoea/hypopnoea index (AHI) 14 (5.2)). On one night patients slept in continuous HRH (85 (4)%, range 80-93%) and on the other in LRH (16 (4)%, range 11-22%). RESULTS—The AHI was similar on the HRH and LRH nights (mean difference 3; 95% CI -2 to 9, p = 0.20) and no statistically significant differences in AHI were observed on the two nights after standardising for body position and sleep stage. Sleep stage distribution and the proportion of time spent in the supine position were similar on the HRH and LRH nights. The number of non-respiratory arousals was also similar on the two nights. CONCLUSION—Altering ambient humidity alone has no significant impact on the severity of OSA.
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Selected References
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- Altman D. G. Statistics and ethics in medical research: III How large a sample? Br Med J. 1980 Nov 15;281(6251):1336–1338. doi: 10.1136/bmj.281.6251.1336. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Charbonneau M., Marin J. M., Olha A., Kimoff R. J., Levy R. D., Cosio M. G. Changes in obstructive sleep apnea characteristics through the night. Chest. 1994 Dec;106(6):1695–1701. doi: 10.1378/chest.106.6.1695. [DOI] [PubMed] [Google Scholar]
- Hsu S. H., Strohl K. P., Jamieson A. M. Role of viscoelasticity in tube model of airway reopening. I. Nonnewtonian sols. J Appl Physiol (1985) 1994 Jun;76(6):2481–2489. doi: 10.1152/jappl.1994.76.6.2481. [DOI] [PubMed] [Google Scholar]
- Jokic R., Klimaszewski A., Mink J., Fitzpatrick M. F. Surface tension forces in sleep apnea: the role of a soft tissue lubricant: a randomized double-blind, placebo-controlled trial. Am J Respir Crit Care Med. 1998 May;157(5 Pt 1):1522–1525. doi: 10.1164/ajrccm.157.5.9708070. [DOI] [PubMed] [Google Scholar]
- Kuna S. T., Sant'Ambrogio F. B., Sant'Ambrogio G. Effect of airway surface liquid composition on laryngeal muscle activation. Sleep. 1996 Dec;19(10 Suppl):S180–S183. doi: 10.1093/sleep/19.suppl_10.180. [DOI] [PubMed] [Google Scholar]
- Miki H., Hida W., Kikuchi Y., Chonan T., Satoh M., Iwase N., Takishima T. Effects of pharyngeal lubrication on the opening of obstructed upper airway. J Appl Physiol (1985) 1992 Jun;72(6):2311–2316. doi: 10.1152/jappl.1992.72.6.2311. [DOI] [PubMed] [Google Scholar]
- Van der Touw T., Crawford A. B., Wheatley J. R. Effects of a synthetic lung surfactant on pharyngeal patency in awake human subjects. J Appl Physiol (1985) 1997 Jan;82(1):78–85. doi: 10.1152/jappl.1997.82.1.78. [DOI] [PubMed] [Google Scholar]
- Widdicombe J. G., Davies A. The effects of a mixture of surface-active agents (Sonarex) on upper airways resistance and snoring in anaesthetized dogs. Eur Respir J. 1988 Oct;1(9):785–791. [PubMed] [Google Scholar]